This invention relates to artificial aquaria, especially those with artificial aquatic creatures.
Aquaria are popular fixtures in homes and offices as well as other public venues, such as hotels and restaurants. In addition to providing an impressive display of fish and other marine life such as invertebrates, coral, and/or plants, aquaria are also valued for their soothing effect on observers.
Although the benefits of an aquarium are great, large amounts of time and money are required to set up and maintain an aquarium. In addition to buying the equipment necessary to set up an aquarium (at minimum, a tank, gravel or sand, filters, heaters, and animals), cleaning, feeding, and restocking an aquarium require time and money as well as a certain level of expertise to ensure that the water quality (salinity, pH, nitrite levels, temperature, etc.) is acceptable, the tank""s inhabitants are receiving the correct diet, and the tank""s occupants can peacefully coexist. xe2x80x9cCatastrophicxe2x80x9d events, such as disease, tank leaks, or power failures which disable filters and heaters, can kill off all tank inhabitants; these events are not uncommon and may occur regardless of the aquarist""s experience and precautions to ensure these events do not happen.
There are also environmental concerns associated with keeping aquariums, particularly saltwater tanks. In addition to the threat posed by pollution, coral reefs are also endangered because both the coral and reef life are xe2x80x9charvestedxe2x80x9d to provide material for aquariums. Many species of fish and other marine life which cannot exist in captivity (generally because of issues related to the animal""s food supply) are captured and sold to unsuspecting aquarists. Furthermore, most marine species do not breed in captivity, so the demand for marine creatures that are caught in their natural habitat is likely to continue unabated.
In addition, xe2x80x9cbiological pollutionxe2x80x9d from escaped aquaria organisms poses an even greater potential hazard. For example, an algae believed to have been introduced into coastal waters by disposal of tank water into a municipal water disposal threatens to overwhelm and displace native algae in the Mediterranean and California, perhaps irreversibly altering these ecosystems.
Some reefs are now being designated as xe2x80x9cno-takexe2x80x9d ecological reserves, meaning that the removal of any marine organism from a protected reef is prohibited. While protection for reefs is welcome from an environmental point of view, it is likely that the cost of fish, coral, and other marine organisms taken from unprotected reefs will increase as a result of this protection. Consequently, the cost of keeping a marine aquarium will also increase.
Given these problems, an artificial aquarium is an attractive proposition to those who wish to enjoy the benefits of an aquarium without the drawbacks of aquarium ownership and maintenance. The prior art contains several examples of artificial aquaria.
U.S. Pat. No. 4,578,044 discloses a toy aquarium containing a toy fish having an interior magnet and a base with a permanent magnet. A magnetic coil in the base generates magnetic force; a change in the polarity of lines of this magnetic force causes the permanent magnet to move. The movement of the permanent magnet is transmitted to the toy fish by means tethering the toy fish to the base.
U.S. Pat. No. 4,691,459 discloses an artificial aquarium with a whirlpool pump which causes circular movement of the water in the aquarium tank. This circular movement causes weighted toy fish in the aquarium to move. A baffle prevents the toy fish from being sucked into the whirlpool pump.
U.S. Pat. Nos. 5,301,444; 5,463,826, and 5,685,096 are artificial aquaria containing artificial fish with magnets. Rotating magnets generate magnetic fields at different speeds, causing the fish to move around.
U.S. Pat. No. 6,148,770 discloses an artificial aquarium with ornamental features (artificial jellyfish, for instance) which move in response to a changing magnetic field created by magnets in the base. The ornamental features have magnets and are weighted or otherwise secured so they do not float to the top.
None of the prior art discussed here discloses an artificial aquarium where the artificial fish display realistic behavior (eating, fighting, etc.). It is an object of this invention to provide a mechanism that enables artificial fish to simulate realistic behavior.
None of the prior art discussed here discloses an artificial aquarium that employs both waterflow and magnetic fields to make artificial fish move.
An artificial aquarium is stocked with artificial aquatic creatures, such as fish, as well as artificial rocks and corals to provide a realistic simulation of a fish tank with live creatures. Each of the artificial creatures has a slight negative buoyancy when submerged in water. Additionally, the creatures each have magnets encased within their bodies.
There are two mechanisms which cause the creatures to move around the tank: water flow and magnetic fields. One or more water pumps circulate water in the tank, creating a xe2x80x9ccurrentxe2x80x9d which causes the artificial creatures to move around the tank as if they were swimming. In addition to the water pump, a number of electromagnets are placed around the tank, some in a central column in the tank, others within artificial rocks and coral. A programmable logic controller controls the activation of the electromagnets. The fields generated by these electromagnets attract and repulse the artificial creatures. The artificial creatures move in a life-like manner due to the movement created by the combination of the magnetic fields and the water flow within the tank.
Realistic behavior, such as feeding and hiding, can also be simulated. As noted above, the activation of the electromagnets is controlled by a programmable logic controller. Inputs to the logic controller, such as optical sensors placed around the tank, can cause the controller to either activate or deactivate the electromagnets placed around the tank. For instance, if an optical sensor placed near one of the artificial corals detects an artificial creature passing by, it can signal the programmable logic controller which in turn activates the electromagnet within the artificial coral. The activated electromagnet attracts the magnet embedded within the creature. As a result of this attraction, the creature appears to be feeding on the coral. The logic controller can deactivate the magnet after a certain period of time, causing the creature to move away from the coral as it drifts with the flow.